Starting the LiveCD bring me up to a black screen only with a mouse pointer (movable) on it. Back to start I select the "verbose" mode. NR 16 bring me up the Desktop in full 2D support and correct resolution. As graphic-driver he gives me the NV46. Now I start to install NR 16 all works fine. After the restart I get the nice looking Ozymandias start screen picture, hear the startup jingle and that it. No Desktop appears (automatic login activated). I wait some minutes but nothing changed.

booting with recovery mode works. Brings me up the Desktop at Software-mode. I start to edit with nano as you suggested.The answer is "no such file or directory" as I save the new created file. So I'm not able to write these file.

4th October 2015, 14:28 Edited(This post was last modified: 4th October 2015, 14:29 by AJSlye.)

Yes, in recovery mode that file wouldn't exist if I remember correctly.
I just read your other post in Deutsch and noticed that you also tried the New Rolling release ISO.
Did you have the same issue booting that ISO up using the non-free (Nvidia Proprietary drivers) option?
I still think the issue is that the compositor is failing using the free opensource driver with your Nvidia Geforce Go 7400.

4th October 2015, 19:46 Edited(This post was last modified: 4th October 2015, 20:23 by AJSlye.)

My apologizes, I just noticed I gave you the command wrong. What I gave you was pointing at ./config/kwinrc off of the root directory, which doesn't exist and you would have needed to be root to create anyway.

For deactivating the effects on the fly you can also press Shift+Alt+F12.
The GeForce Go 7400 does not support all the effects that the nouveau driver tells kwin that it can.
In general as OpenGL 1 isn't there anymore as option for KWin you either need to stick to XRender for effects (which should work everywhere as it is using the CPU for the effects) or you could try EGL (OpenGL ES) which might work better or at all with your graphicscard. (though I did not test that as my Geforce 7300 Go [same chip] Laptop is basically more or less broken)